Low end torque starting to bug anybody else?

[mPlasticDesign]

Originally Posted by stingray23

You're damn right I picked the right car

Right car.....wrong forum bub!

http://forums.corvetteforum.com/index.php

[TRZ06]

Originally Posted by Jim Pearce

I can't attest to the numbers but the poster was referring to multiplied torque. The Corvettes have much taller gearing. Intuitively, the M3 would be putting down more thrust than a garden variety C6 since it's heavier but accelerates just as fast up to 150 mph or so.

You are still waaay off. The standard C6 has more HP and TQ than even the C5 Z06, while the weight is not much different. Even with the gearing, the C6 will take the M3 to 150MPH

The M3's are great for what they are, a GT and in my case a 4 door GT, but they are not the all out sports car that some seem to think.

[BimmerBoomer]

Originally Posted by TRZ06

You are still waaay off. The standard C6 has more HP and TQ than even the C5 Z06, while the weight is not much different. Even with the gearing, the C6 will take the M3 to 150MPH

The M3's are great for what they are, a GT and in my case a 4 door GT, but they are not the all out sports car that some seem to think.

I'll use C&D's test figures for an '06 C6 6-spd. and an '09 E92 DCT. 0-150 was 26.8 seconds for the C6, 25.9 for the M3. Test weight of the C6 was 3280 pounds, test weight of the M3 3700 pounds. While the peak engine torque of the M3 is only 295 ft. lb. @ 3900 versus 400 ft. lb. @ 4400 for the C6, somehow the M3 managed to get more work done.

Let's take a look at first gear. The 'vette goes 7.6 mph per 1000 rpm in 1st, the M3 5.1. As a crude approximation and assuming equal drivetrain losses, the M3 produces close to 10% more maximum torque at the wheel than the C6 - ((7.6/5.1)/(295/400)-1)x100%.

[330CIZHP]

I will have to agree with Jim.

Not to magazine race, but here is the grand sport C6 with 436 HP vs 420 HP M3:

Stock they are both neck and neck uptil the 1/4 mile and then the C6 Corvette gains only a 1 second advantage till 155 mph (at 155 mph, 1 second is less than a car length):

http://www.caranddriver.com/var/ezfl...28dc1e1622.pdf

http://www.caranddriver.com/var/ezfl...b6de3d3692.pdf

M3 is 3600 lbs vs 3350 lbs for the grand sport. Yet, M3 is very close in acceleration to the C6 grand sport. Secret is the aggressive gearing afforded by the luxury of an enormous powerband uptil 8400 rpm spanning 6500 rpm.

Originally Posted by Jim Pearce

I'll use C&D's test figures for an '06 C6 6-spd. and an '09 E92 DCT. 0-150 was 26.8 seconds for the C6, 25.9 for the M3. Test weight of the C6 was 3280 pounds, test weight of the M3 3700 pounds. While the peak engine torque of the M3 is only 295 ft. lb. @ 3900 versus 400 ft. lb. @ 4400 for the C6, somehow the M3 managed to get more work done.

Let's take a look at first gear. The 'vette goes 7.6 mph per 1000 rpm in 1st, the M3 5.1. As a crude approximation and assuming equal drivetrain losses, the M3 produces close to 10% more maximum torque at the wheel than the C6 - ((7.6/5.1)/(295/400)-1)x100%.

[bruce.augenstein@comcast.]

Originally Posted by Jim Pearce

I'll use C&D's test figures for an '06 C6 6-spd. and an '09 E92 DCT. 0-150 was 26.8 seconds for the C6, 25.9 for the M3. Test weight of the C6 was 3280 pounds, test weight of the M3 3700 pounds. While the peak engine torque of the M3 is only 295 ft. lb. @ 3900 versus 400 ft. lb. @ 4400 for the C6, somehow the M3 managed to get more work done...

Dunno about the '06 Vette, but the current one does 0-150 in 23.7, according to Car & Driver in the November issue.

In my opinion, the M3 is something of an overachiever given its specs, and it stays close to the Vette for various reasons - but it'll be behind everywhere except perhaps the first part of a standing start race.

Bruce

[xxe92xx]

Originally Posted by footie

I can tell you that my experience in driving everything from humble city cars to full blown exotics is vast and I know a hell of a lot about the benefits and downfalls of all types of engines.

righhtt....

The very fact you suggest an automatic as a fix proves to me that you don't know as much as you think.


hes not suggesting an automatic as a fix, he means that the C63 offers the torque fix that many people are looking for, but who knows how many of you "actually know" how to drive this car, this is a "drivers" car...also the flat torque curve is one of the many things that makes this motor great

P.S.
Surprisingly the 335i has been mentioned very little because it's not the best example of the breed to chose from and M-Division has something much better in mind for the next M3.

IMO to the people who want more torque chose the wrong car

[bruce.augenstein@comcast.]

Originally Posted by 330CIZHP

I will have to agree with Jim.

Not to magazine race, but here is the grand sport C6 with 436 HP vs 420 HP M3:

Stock they are both neck and neck uptil the 1/4 mile and then the C6 Corvette gains only a 1 second advantage till 155 mph (at 155 mph, 1 second is less than a car length):

M3 is 3600 lbs vs 3350 lbs for the grand sport. Yet, M3 is very close in acceleration to the C6 grand sport. Secret is the aggressive gearing afforded by the luxury of an enormous powerband uptil 8400 rpm spanning 6500 rpm.

Is this the new math?

Going by your supplied data, the Vette is about one full car length ahead at the quarter mile, and going three mph faster at that point. Let's guess that the Vette more or less maintains that speed differential for the next 11 seconds or so that it takes it to get to 150 mph. That's an additional 48 feet, for a total of about four car lengths at 150 mph and still pulling away.

If the M3 starts whittling away at the Vette's speed differential between 113 and 150 mph (by dint of closer-spaced gearing up top), the Vette is still pulling away, as dictated by the fact that it reaches 150 mph first.

So, what, maybe three car lengths if the M3 is a top-end fiend?

Your bias is affecting your math.

[footie]

Originally Posted by xxe92xx

IMO to the people who want more torque chose the wrong car

Well that's a matter of opinion, many including myself love the M3, it's just that small part about it's lack of torque below it's sweet spot which unfortunately is a smaller sweet spot than I would have liked. Everything else about the car is pretty perfect, great ride quality regarding the handling, nice brakes and sweet steering, the awd thing is something that I would have preferred but would never be a deal breaker, after all I am now driving an XF which is once again rwd.

So in my opinion I had the right car, only it didn't have the right engine for me. Roll on 2012 and the next M3, well that is if Audi don't have an RS4 out at the same time.

[xxe92xx]

Originally Posted by footie

Well that's a matter of opinion, many including myself love the M3, it's just that small part about it's lack of torque below it's sweet spot which unfortunately is a smaller sweet spot than I would have liked. Everything else about the car is pretty perfect, great ride quality regarding the handling, nice brakes and sweet steering, the awd thing is something that I would have preferred but would never be a deal breaker, after all I am now driving an XF which is once again rwd.

So in my opinion I had the right car, only it didn't have the right engine for me. Roll on 2012 and the next M3, well that is if Audi don't have an RS4 out at the same time.

yea im looking forward to seeing what 2012 brings

[330CIZHP]

If anything, it must be your own bias in your mind. The only time Corvette pulls aways from M3 was between 60 - 100 mph and then M3 reels it back in continously closing the gap to less than half a car length by 1/4 mile (which is why the trap speed is higher in Corvette).

I was going strictly by times that the Corvette reached 150 mph 1 second quicker than the M3 and the fact that M3 starts to gain after 100 mph.

Theoratically, despite the difference between the trap speeds at the 1/4 mile, M3 goes neck and neck till 60 mph at 4.1 seconds and then Corvette gains a few car lengths seeing their 0- 100 mph difference of 0.6 of a second in favor of the Corvette (9.2 vs 9.8) and then M3 gains big time over the next 13 mph making it to the quarter mile almost neck and neck (less than a car length at 0.1 seconds). Seeing the trap speeds, M3 reaches 115 mph about 0.2 - 0.3 seconds after the Corvette yet, it reaches 150 mph just 1 second behind. That means M3 made gains between 115 - 150 mph. The difference in trap speed came from the gains Corvette made between 60 - 100 mph of 0.6 seconds (about 3 - 4 car lengths) and then M3 continuously reels it back.

Originally Posted by bruce.augenstein@comcast.

Is this the new math?

Going by your supplied data, the Vette is about one full car length ahead at the quarter mile, and going three mph faster at that point. Let's guess that the Vette more or less maintains that speed differential for the next 11 seconds or so that it takes it to get to 150 mph. That's an additional 48 feet, for a total of about four car lengths at 150 mph and still pulling away.

If the M3 starts whittling away at the Vette's speed differential between 113 and 150 mph (by dint of closer-spaced gearing up top), the Vette is still pulling away, as dictated by the fact that it reaches 150 mph first.

So, what, maybe three car lengths if the M3 is a top-end fiend?

Your bias is affecting your math.

[King Tut]

Originally Posted by footie

The very fact you suggest an automatic as a fix proves to me that you don't know as much as you think.

Last time I checked the C63 isn't offered with anything else. My point was anyone complaining about the torque of the M3 doesn't understand it is a 4.0L engine making over 100 hp per liter with a perfectly flat torque curve. If all you want is to brag about torque numbers at 2000 RPM then you bought the wrong car.

[waremark]

In traffic I generally leave my M3 DCT in D2, and it spends a lot of its time at 1,500 rpm. It happily keeps up with or ahead of the traffic without ever going over 4,000, while making a glorious sound. Out on the back roads, it is possible and enjoyable to drive really quickly without going over 5,000. I like the feel and sound of the sprint for the redline, but I can enjoy the engine without going there too often.

Today I drove a Z4 3.5i (same engine as the 335 I think). Sure it was quick between 2,000 and 5,000, but it sounded so ordinary by comparison with the M3, and over 5,000 it became less pleasant, just when the M3 would have been getting into its stride.

I guess I bought the right car for me.

[waremark]

So you are going 90 by the end of your 5 car overtake? (Apologies to anyone who cannot remember the 5 car overtake posts). Let's say the vehicles you are overtaking are up to 45 by now. Can anyone work out how much space you need to avoid crashing if car 2 pulls out in front of you to overtake car 1?

[bruce.augenstein@comcast.]

Originally Posted by 330CIZHP

If anything, it must be your own bias in your mind. The only time Corvette pulls aways from M3 was between 60 - 100 mph and then M3 reels it back in continously closing the gap to less than half a car length by 1/4 mile (which is why the trap speed is higher in Corvette).

I was going strictly by times that the Corvette reached 150 mph 1 second quicker than the M3 and the fact that M3 starts to gain after 100 mph.

First point: You cannot tell where the cars are positioned at any given time based on time to speed. In fact, I would postulate that the M3 is ahead of the Vette at 60.

Second point: A tenth of a second at 113 mph is just over a car length. Do the extremely basic math.

Third point: Even if you use the extremely unreliable method of determining who is ahead based on time to speed, the Vette reaches 100 mph less than a second ahead of the M3, and by more than a second to 150. Therefore, the M3 does not appear to be gaining, even at 150.

Originally Posted by 330CIZHP

Theoratically, despite the difference between the trap speeds at the 1/4 mile, M3 goes neck and neck till 60 mph at 4.1 seconds and then Corvette gains a few car lengths seeing their 0- 100 mph difference of 0.6 of a second in favor of the Corvette (9.2 vs 9.8) and then M3 gains big time over the next 13 mph making it to the quarter mile almost neck and neck (less than a car length at 0.1 seconds). Seeing the trap speeds, M3 reaches 115 mph about 0.2 - 0.3 seconds after the Corvette yet, it reaches 150 mph just 1 second behind. That means M3 made gains between 115 - 150 mph. The difference in trap speed came from the gains Corvette made between 60 - 100 mph of 0.6 seconds (about 3 - 4 car lengths) and then M3 continuously reels it back.

Last point: With the Vette trapping at three mph faster than the M3, it'll take the M3 well over a half second to get to 116 mph. Again, time to speed and time to distance are essentially unrelated, and the M3 is only a little more than a car length behind at that point - which is part of the reason that I characterize the bimmer as an overachiever, given its specs.

[TRZ06]

Originally Posted by 330CIZHP

If anything, it must be your own bias in your mind. The only time Corvette pulls aways from M3 was between 60 - 100 mph and then M3 reels it back in continously closing the gap to less than half a car length by 1/4 mile (which is why the trap speed is higher in Corvette).

I was going strictly by times that the Corvette reached 150 mph 1 second quicker than the M3 and the fact that M3 starts to gain after 100 mph.

Theoratically, despite the difference between the trap speeds at the 1/4 mile, M3 goes neck and neck till 60 mph at 4.1 seconds and then Corvette gains a few car lengths seeing their 0- 100 mph difference of 0.6 of a second in favor of the Corvette (9.2 vs 9.8) and then M3 gains big time over the next 13 mph making it to the quarter mile almost neck and neck (less than a car length at 0.1 seconds). Seeing the trap speeds, M3 reaches 115 mph about 0.2 - 0.3 seconds after the Corvette yet, it reaches 150 mph just 1 second behind. That means M3 made gains between 115 - 150 mph. The difference in trap speed came from the gains Corvette made between 60 - 100 mph of 0.6 seconds (about 3 - 4 car lengths) and then M3 continuously reels it back.

Hate to burst your bubble, but the M3 does not and can not achieve 4.1 0-60

the M3 is a mid to upper 4 second car.

[-=Hot|Ice=-]

Originally Posted by TRZ06

Hate to burst your bubble, but the M3 does not and can not achieve 4.1 0-60

the M3 is a mid to upper 4 second car.

Sorry to burst your bubble but:


C/D TEST RESULTS:
Zero to 60 mph: 4.3 sec
Zero to 100 mph: 9.9 sec
Zero to 150 mph: 26.0 sec
Street start, 5–60 mph: 4.9 sec
Standing ¼-mile: 12.7 sec @ 113 mph
Top speed (governor limited): 161 mph
Braking, 70–0 mph: 147 ft
Roadholding, 300-ft-dia skidpad: 0.96 g

From Road and Track:

http://www.roadandtrack.com/article....rticle_id=7178


that doesn't look like mid to upper 4's to me. I bet 4.1 could be achieved.

[MVF4Rrider]

Originally Posted by swamp2

Sorry you are sorely mistaken here. Did you bother the read the extensive thread and debate I mentioned? It appears not. Please have a look here. You are arguing that a diff change can and typically will make this modded car accelerate better under any conceivable real world situation than the stock car. Hmmm, this leads to a fairly obvious logical contradiction. Why not just run an infinite (or absolutely enormous FD ratio)? Seriously think about what a car would do if given a FD say 3 times as large as its existing one. Sure it will be producing enormous rear wheel torque and thrust but again there is no such thing as a free lunch. Will it out accelerate the unmodified car by 3 times across any meaningful range? How many gears would it need to reach a similar top speed (or even a similar high track or crusing speed)? How many gear changes would be involved and how often would they occur? This exact same reasoning along with the prior point I made will occur even with a slightly modified FD ratio, just to a lesser extent. You really need to think this problem through more carefully and holistically. You must compare the cars ACROSS shifts not in the very limited case of the results in one gear only. The acceleration difference between first and second gear is nearly 50% different in the M3 (less difference between successive gears of course). Do you claim that spending a half second or so (maybe more, maybe less depending on how large of a change to the FD ratio one made) would not impact in a very significant way any measure of acceleration where a 1-2 shift is involved?

I absolutely am not claiming that FD ratios are fully optimized in all sporty cars, I am also not claiming that some metrics can not be improved with FD modifications. I am not claiming that modding your FD won't make your call FEEL a bit faster. However, I am vehemently arguing, in the case of the M3 ,there is little to nothing to be gained in most real world acceleration metrics through a FD mod. The benefits of either 7 gears and DCT vs. 6 or even a few percent hp increase will trump what you would get from any reasonable FD mod.

Really, think very carefully about what a huge FD modification would mean. Also think carefully about an acceleration run involving multiple gears and the disadvantage of spending more time in gears offering less torque. There is no such thing as a free lunch here.

Sigh

How frustrating when trying to educate the masses. You clearly don't understand the concept of multiplied torque, as you cite "% additional HP" as an actual variable. You probably think the same car at 3,000 rpm in 2nd gear is putting down the same torque to the pavement as the same car at 3,000 rpms in 4th gear. Why not, right? It's the same rpm and therefore the torque would be equal.

Do you understand that a one-step change in FD equals an 8% increase in total torque across the entire rev counter (every single rpm) in each and every gear? Can you not realize how much additional power that is, and that it would cause the car to reach terminal velocity in each gear quicker as the revs build quicker. You think this additional multiplied torque (essentially - total torque) increase has a negative affect on performance? This is not a radical example requiring dozens of gears as you say. It is a moderate increase that makes a real acceleration change, not a perceived one. It makes the power band more usable in both normal driving situations and in spirited driving. In every day, the 8% increase in torque means you can use less rpms per gear to yield the same rate of acceleration you enjoy. Or when you opt to put your foot in it the throttle response is more crisp and acceleration is quicker. It is IMPOSSIBLE to have more applied torque (at a mere 8%) and for acceleration in a given gear to be less, or even equal. That doesn’t mean I’m ignoring gear changes and that affect on real driving. I can assure you no variable escapes me, whether I write to it or not. My argument applies to only the affects of a single-step rear end gear change and does not speak to any other type modding, including engine mods. Only a novice wouldn’t be able to use that extra grunt to their advantage. People here want more torque. This is a sure way to deliver it without any adverse affects (although a very slight decrease in fuel economy at cruise in top gear due to a small increase in rpm, which proves the gear change has a power affect). In fact, both Dinan and AC Schnitzer state unequivocally it’s the best bang for the buck mod and makes the most pronounced improvement in acceleration in consideration to drivability (keeps the torque curve as is), yet you argue against and offer inane remarks such as “no such thing as a free lunch.” Dinan and AC Schnitzer must be idiots I suppose? I guess they didn’t read your referenced thread either. Not to mention, you think a few % HP increase will produce more tangible results than FD change? Do you realize what you are saying? First, that % change you speak of isn’t consistent across the rev counter and second, it would have to be a hell of a lot more than a few % to equal an 8% increase in total torque to the ground. How much more HP would the car need to shave a half-second 0-62? That’s what you’re up against. And no one is saying you can’t do both. But total torque is what affects acceleration the most, and gearing is the best way to get it without making a peaky power band which is not necessarily a good thing. IMO, BMW M cars are geared a tad too tall. I understand why, which is predominantly biased toward fuel economy and to limit stress to the drive train. Nothing wrong with that. In fact, actual automotive enthusiasts are a minority of owners worldwide (especially in the US). I wonder why?

[MVF4Rrider]

Originally Posted by -=Hot|Ice=-

Sorry to burst your bubble but:


C/D TEST RESULTS:
Zero to 60 mph: 4.3 sec
Zero to 100 mph: 9.9 sec
Zero to 150 mph: 26.0 sec
Street start, 5–60 mph: 4.9 sec
Standing ¼-mile: 12.7 sec @ 113 mph
Top speed (governor limited): 161 mph
Braking, 70–0 mph: 147 ft
Roadholding, 300-ft-dia skidpad: 0.96 g


that doesn't look like mid to upper 4's to me. I bet 4.1 could be achieved.

I don't trust any times from US mags. For one, they are all climate corrected so it's not the actual "best" time. Secondly, all the US mags have great differences in posted numbers, which usually means the avg person chooses the quickest time for the car they like and the slowest times for the cars they use for comparative purposes. I've seen it too many times on forums. In addition, it's only fair to put the same rubber on all cars but that'll never happen. They also never tell you if sport mode or launch control is used (if applicable). For sure the DCT is quicker than the 6MT. Does your source cite which car is used? Hair splitting like this makes me enjoy my cars and thinking about them less fun. Cars are a compromise among factors such as performance, economy, safety, and style, etc. Any manufacturer can improve the performance envelop if they so choose, but it's usually at the expense of another factor.

[Sleeper519]

Originally Posted by -=Hot|Ice=-

Sorry to burst your bubble but:


C/D TEST RESULTS:
Zero to 60 mph: 4.3 sec
Zero to 100 mph: 9.9 sec
Zero to 150 mph: 26.0 sec
Street start, 5–60 mph: 4.9 sec
Standing ¼-mile: 12.7 sec @ 113 mph
Top speed (governor limited): 161 mph
Braking, 70–0 mph: 147 ft
Roadholding, 300-ft-dia skidpad: 0.96 g

From Road and Track:

http://www.roadandtrack.com/article....rticle_id=7178


that doesn't look like mid to upper 4's to me. I bet 4.1 could be achieved.

And add this one to the list from R & T...

http://www.roadandtrack.com/assets/d..._datapanel.pdf

0-60 = 4.1 , 1/4mi = 12.5

[MVF4Rrider]

Originally Posted by Jim Pearce

I guess Dinan managed to fool me for 180,000 kilometers. http://www.dinancars.com/assets/File...A%20EDITED.pdf

The real problem is the sheer amount of torque - not the distribution, which is actually improved. The car pulled strongly to 5700 or so. I considered getting an LSD but ultimately a car with this much torque needs an active differential, which I'm sure the F30 M3 will get.

I'm not saying it won't be quicker. But the often substantial increase in engine output doesn't exactly translate to a congruent substantial improvement in acceleration/overall performance, especially when the additional torque overwhelms the chassis, transmission, clutch, etc. Plus, I don't like peaky torque curves. And I sure don't like losing 100+ lb-ft or torque in the upper 2,000 rpms of the rev counter. I'm also an avid sport motorcyclist (since the 70s) and I like to make engines scream. Same for cars. I hate revving motors like the N54 and have it make more noise and simultaneously feel the torque diminishing rapidly. Super disappointing. Having gobs of off-idle torque and an anemic upper end does not compute in my book. No tuner can get by this with the N54. They all radically reduce boost at the upper end to save the motor from grenading.

[Sleeper519]

Originally Posted by Singletrack

If you want monster low end torque and gas mileage, then you should buy a turbo...

....if you truly want monster low-end torque, then buy a John Deere tractor.

[BimmerBoomer]

Originally Posted by MVF4Rrider

I'm not saying it won't be quicker. But the often substantial increase in engine output doesn't exactly translate to a congruent substantial improvement in acceleration/overall performance, especially when the additional torque overwhelms the chassis, transmission, clutch, etc. Plus, I don't peaky torque curves. And I sure don't like losing 100+ lb-ft or torque in the upper 2,000 rpms of the rev counter. I'm also an avid sport motorcyclist (since the 70s) and I like to make engines scream. Same for cars. I hate revving motors like the N54 and have it make more noise and simultaneously feel the torque diminishing rapidly. Super disappointing. Having gobs of off-idle torque and an anemic upper end does not compute in my book. No tuner can get by this with the N54. They all radically reduce boost at the upper end to save the motor from grenading.

Neither the clutch nor the transmission were overwhelmed. Full throttle in second gear induced power squat - otherwise the car would stay right with an M3. If BMW can get a turbo engine to pull strongly from 1500 to 6500 rpm in the F30 M3 that'll be enough for me. Oh, and for long rides I far prefer my Sprint 1050 ST's relaxed triple (race can) to any four I've ridden - and I do demo rides nearly every year.